Matthew,  I was thinking about your problem.  Being a digital design
engineer by trade, I will tell you what I know.  If you want to digitize
the music and store it in a ROM, you do not need anything as elaborate
or expensive as a microcontroller to be able to play it back.  You can
just use a counter to sequentially step through the addresses in the
ROM.

However, there is a bit more to this problem.  It is not a one-chip
solution.  You would need the ROM, a counter, a digital to analog
converter, as well as some transistors to amplify the signal.  I would
be more than happy to discuss with you exactly how to design a small
circuit board to do what you want offline.  ROM programmers are not
that expensive any more and I'll bet you could buy a basic one for
under $300.

However, the music stored in greeting cards as discussed by Colin
MacKinnon is done by a different method.  It is not digitized at all,
but stored as a series of analog voltages in a specialized chip.
The company that makes these chips is called ISD (Information Storage
Devices).

They sell a one-chip solution that will record sound via a microphone
and directly drive a small speaker with no additional amplification
needed.  They sell their chips in both bare die, the so called "blob"
chips that Colin speaks of, and packaged form.  They sell different
models that hold anywhere from 10 seconds to 8 minutes of sound.  In
quantities under 10, these sell anywhere from $4.50 to $11.13 each.

The cheapest programmer they sell costs $137.50.  But, you don't
even really need it.  The chip is also designed to sample a microphone
directly.  You can buy the chips and the programmer at Digikey
(www.digikey.com).  They sell to the public with a minimum order of
$25.  I think I have also seen the chips sold at Radio Shack.  If you
would like to pursue this method, I would be happy to help you.

Benjamin Haass